Organic photoconductive materials formed by condensing photoconductive and dyestuff reactants

ABSTRACT

A light-transparent photoconductive material for use in electrophotography is the reaction product obtained by condensing A. AN ORGANIC PHOTOCONDUCTIVE COMPOUND CONTAINING AN AMINO AND/OR HYDROXYL GROUP AND B. A REACTIVE COLORED COMPOUND CONTAINING AN ACTIVE HALOGEN ATOM; OR BY CONDENSING A. AN ORGANIC PHOTOCONDUCTIVE COMPOUND CONTAINING AN ACTIVE HALOGEN ATOM AND B. A REACTIVE COLORED COMPOUND CONTAINING AN AMINO AND/OR HYDROXYL GROUP.

Nagashima et al.

ORGANIC PHOTOCONDUCTIVE MATERIALS FORMED BY CONDENSING- PHOTOCONDUCTIVEAND DYESTUFF REACTANTS Inventors: Shinichiro Nagashima, Kaichi Tsuchiya,both of Tokyo, Japan Assignee: Canon Inc., Tokyo, Japan Filed: Dec. 29,1969 App1.No.: 888,886

u.s. c1. ..96/l.5, 260/249.5, 260/249.6, 260/249.8

1m. Cl. ..G03g 5/04 Field Of Search ..8/8.1 E; 260/249.5, 249.6,260/249.8; 296/15 I References Cited UNITED STATES PATENTS 3/1954Scalera et 1. ..260/249 ]March 20, 1973 2,950,196 8/1960 Carroll et a1...96/100 3,054,795 9/ 1962 Staeuble et a1. ..260/249 3,060,180 10/ 1962Staeuble et a1. 260/249 3,157,651 11/1964 Atkinson et a1. .260/2481,663,474 3/ 1928 Ackermann ..8/1 E 3,261,826 7/1966 Andrew ..260/153Primary Examiner-John C. Cooper, III

Attorney- McGlew and Toren ABSTRACT A light-transparent photoconductivematerial for use in electrophotography is the reaction product obtainedby condensing a. an organic photoconductive compound containing an aminoand/or hydroxyl group and b. a reactive colored compound containing anactive halogen atom; or by condensing v a. an organic photoconductivecompound containing an active halogen atom and b. a reactive coloredcompound containing an amino and/or hydroxyl'group.

3 Claims, No Drawings ORGANIC PHOTOCONDUCTIVE MATERIALS FORMED BYCONDENSING PHOTOCONDUCTIVE AND DYESTUFF REACTANTS FIELD OF INVENTION Thepresent invention 'relates to novel colored or color developing organicphotoconductive materials which are useful as developing orphotosensitive materials in electrophotography or related techniques.

BACKGROUND INFORMATION AND PRIOR ART The present inventors, who haveinvestigated the.

reproduction of multi-colored or naturally colored images as one of theaims in electrophotography, obtained good results when they used coloredorganic photoconductive materials as toner in the production ofsuperimposed images.

For example, in the reproduction of naturally colored images on apanchromatically sensitized zinc oxide photoconductive layer, anegatively charged photoconductive layer is first exposed to the objectthrough a red filter and then developed with a cyancolored toner.

The photoconductive layer is then again charged in a negative sense andexposed to the object through a green filter to obtain a negativelycharged image which is subsequently developed with a magenta toner.Further, the photoconductive layer is charged negatively, exposed to theobject through a blue filter andv developed with a yellow toner.

In this case, if the images toned in cyan color are electricallyinsulating, they are also charged at the second negative charging andthe charged electricity will not disappear at the following exposure togreen light so that the images produced by the magenta toner inevitablyoverlap the images in cyan. On the other hand, however, if thecyan-colored toner is electrically conducting, the cyan images are notat all charged during the second charging process so that, if the imagesproduced by the second exposure with the green light overlap the blueimages of the first exposure, the magenta toner will never be attachedto the respective part. To overcome the difficulty, the toner has toexhibit photosensitivity in itself.

For obtaining satisfactory results it is, however, not sufficient thatthe toner possesses photosensitivity or photoconductivity. If themagenta toner and the yellow toner are not transparent to light, forexample, the parts where the images of three colors superimpose eachother will not show their mixed color (in other words, will not showblue color at the superimposition of cyan and magenta, not green colorat the superimposition of cyan and yellow), but the color of the toneremployed afterwards covers the color of the previously applied toner, sothat the parts where cyan is superimposed by magenta and by yellow showmagenta and ye]- low color, respectively.

In conclusion, the toners, in either dry or wet process of developing,must be of colored materials having photoconductivity and lighttransparency to reproduce naturally colored images byelectrophotography.

Organic photoconductive materials colored with a coloring material andmeeting the above requirements have previously been investigated. Butthe lot-to-lot variation of the coloring materials with respect topurity, solubility etc. often resulted in fluctuation in the quality ofproduct, and therefore reproducible and continuous production of thedevelopers was very difficult. It was also found that the coloringmaterials in the developed images becameblurred during storage and havea tendency to transfer to other matter.

The present inventors continued their effort to eliminate these defectsand finally arrived at the present invention.

I SUMMARY OF INVENTION 'The object of this invention is to providecolored or color developing organic photoconductive materials which aretransparent to light.

An other object of this invention is to provide colored or colordeveloping organic photoconductive materials which do not show blurringand transfer of coloring materials and which can be reproduciblyproduced with constant color characteristics and which are notinfluenced by lot-to-lot variation of the contamination of impurities.

A further object of this invention is to provide colored or colordeveloping organic photoconductive materials for use in photographicdeveloping having favorable light transparency of which the electricalcharacteristics are suited especially to the reproduction ofmulti-colored or naturally colored images.

A further object of this invention is to provide a.

process for producing visible images by employing color developingorganic photoconductive materials as materials for photographicdeveloping and making them to react with a color developing auxiliaryafter the developing process.

An other further object of this inventionis to provide colored or colordeveloping photosensitive materials for use in electrophotography whichhave a photosensitive layer containing colored or color developing or?ganic photoconductive materials.

The present invention can provide colored organic photoconductivematerials for use in electrophotography by the reaction of organicphotoconductive sub.- stances with reactive colored components. Thereactive colored components refer to reactive coloring materials andreactive color developing components in general.

In other words, the present invention relates to a procedure forobtaining colored organic photoconductive materials for use inelectrophotography by the reaction of organic photoconductive materialswith reactive coloring materials, and also to a process for obtainingcolor developing organic photoconductive materials for use inelectrophotography by the reaction of organic photoconductive substanceswith reactive color developing components.

. The colored or color developing organic photoconductive materials ofthis invention can be obtained by chemically combining an organicphotoconductive substance having at least one amino or hydroxy groupwith a coloring or a color developing component having at least oneactive halogen atom.

Further the colored or color developing organic photoconductivematerials of this invention can be obtained by chemically combininganorganic photoconductive substance having at least one active halogenatom with a coloring or a color developing component having at least oneamino or hydroxyl group.

The resulting products of the chemical combination are not onlyphotoconductive but also colored and light-transparent, and the colorson them are free from defects, e.g. they do not become blurred ortransferred because the coloring materials are chemically combined, notin the same manner as in a usual dyeing, with the photoconductivesubstances, and the steadiness of color was maintained for every productowing to the constant ratio of combining molecules in the chemicalcombination.

When the color developing organic photoconductive I materials of thisinvention are employed as materials for photographic developing, theycan either be reacted beforehand with a color developing auxiliary todevelop coloration, or they are used as they are as materials fordeveloping and are reacted, after developed, with the color developingauxiliary to develop coloration.

The colored or color developing organic photoconductive materials may bepulverized in a ball-mill, a roll-mill and an atomizer to use them astoner for use as dry or wet developing agent, or they may be used incombination with other colored substances or vehicle resins, in the caseof which the vehicle resins include, for example, rosin and thederivatives thereof, styrene resin, alkyd resin, terpene resin, xyleneresin, straight chain hydrocarbon resin, phenol resin, epoxy resin andacrylic resin. These toners may be used as developer for negativelycharged images in single or in combination with carrier materials suchas glass beads, iron powder and furs.

When the organic photoconductive materials are used as wet developingagent, the materials are dispersed in a carrier liquid. For the carrierliquid, an insulating liquid widely know as carrier liquid for a liquiddeveloper, for example, aliphatic hydrocarbons, cycloaliphatichydrocarbons, halogenated hydrocarbons, aromatic hydrocarbons such aspentane, hexane, gasoline, kerosene, mineral spirit, cyclohexane, carbontetrachloride, perchloroethylene and naphtha and silicone oil waxes maybe used and in aspecial case water may be used.

When the colored or color developing organic photoconductive materialsof this invention are utilized as the photosensitive materials for usein electrophotography, binding resin or plasticizer is not required forthe organic photoconductive materials having capability of formingfilms, but use of 30 100 percent by weight of a binding resin is desiredfor the photoconductive materials which do not have capability offorming films. In this case, a plasticizer may be added in the amount of5 100 percent by weight, alone or in combination with an otherphotoconductive material, to further improve the quality of the coatingfilms.

Binding resins referred to above include, for example, polystyreneresin, polyvinyl chloride, phenol resin, polyvinyl acetate, polyvinylacetal, epoxy resin, xylene resin, alkyd resin, polycarbonate resin,acrylonitrile styrene resin.

As supports for the photosensitive materials may be used, for example,metallic plates of aluminum, copper, zinc and silver, papers treated sothat solvents could not enter the interior, aluminum laminated paper,filmsof synthetic resins in which a plasticizer is contained, andsupports the surfaces of which are coated with a metal, a metal oxide ora metal halide as glass, paper, polyethylene, polypropylene,polyethylene terephthalate, polystyrol, polyvinyl chloride,ethylcellulose, cellulose acetate, polyester films and other syntheticresin films. In general, they should have a surface resistance less than10 ohms, preferably less than 10 ohms.

The films of the photosensitive layer can be formed on the' supports ina conventional manner such as, for example, by use of rolls, wire bars,or air knives.

Since the color developing organic photoconductive materials of thisinvention are generally colorless or lightly colored, they have manyadvantages over colored organic photoconductive materials when employedas materials for photographic developing or photosensitive materials.

The most predominant advantage of the materials of this invention asused for materials of photographic developing is as follows. In case ofdeveloping by way of superimposed multi-colored images as describedbefore, for example, if an already colored material for developing isused, the coloration of the first developed image will act as filter inthe subsequent exposures, thus significantly decreasing the apparentsensitivity. However, if a color developing organic photoconductivematerial which is colorless or lightly colored is used, the abovedescribed difficulty will be completely eliminated or at leastminimized.

When these colorless or lightly colored materials are used forphotosensitive materials, unfavorable effects on sensitivity to lightand color could not be observed.

0n the other hand, in synthesizing photoconductive materials, thereaction-of a colored substance with an organic photoconductive compoundshould be carried out fairly slowly in order that the coloring substancebe not decomposed nor faded in the course of reaction. The variousconditions of reaction may, however, be freely selected, when a colordeveloping component is used, because the component is usually of alower molecular weight and more resistant to heat and light than thecoloring substances.

The condensation reaction of the various active halogens and amines ofthis invention is preferably performed-in anhydrous media. Thecondensation reacplayed in the present invention include, for example,12 the following:

-NHz I I NH: 5 \N (!]HCH2 HzN NH:

-OHCH \1 I A, NHZ HzN 1 l i) 8) 0 0H 0H, I I

l OH 1 (20) HzN-@C=CNH1 a m-e m 3 Q \g/ \N 5 7 mcocl (a1) w g N L H 10 aat N 7 Aw ---fi v" 'v-T- m l -Q a s 0001 (33) Br Br H 001 H5Cz \C2H6 lm, l L OH H N The reactive coloringmaterials or compounds having anactive halogen atom or atoms, which may be em- (25) ployed in thepresentinvention, include the following H10 CH1 substances:

H3O H:

N N /CH3 c1 J-NH- -c=1-z -N H N 5:0 0H; (26) /N\ 40 v l 3 01 N H3O \s 4sThe photoconductlve substances havmg an actlve halogen atom or atomsinclude, for example, following 1 $1 substances: Cl-k J-NH-Q N C-N V I II 0C] (28) v N H (2 I (as) 01 OH C 0 Cl 7 o v v (60) 1 CS1 OH 01 OH (as)H (51 W V v Cl0C-N=Nl(flJ-CH;

N01 01 0:2) N l CH F:

(6 I The reactive coloring materials having an amino or a hydroxy groupor groups include, for example, the following substahces: 0H

K/] (59) 1 O 17H:

0 ONH- I N=NCOGl 4o 60) 5 111 I A AOOH 1 l coNI-I- CF K Q 1 5 I 4 NH:(61) H I v H,c0- N=N-o-c-Nm U54) I N0: a .H

i N: @0001 50 N -CO(|JHCONH NH: 1

(64) 0011: Cl J'NII-' -CII- NIICO- on, a

68 v H3O 0'N=NO H c1 1 (m) I ClCH C IhNI-ISOQNIICOCIIzCOOCHa (69) 0 11mm:

ClCH2CHz-NH-SO2 (is) I cicrncmmI socoNH p -cm I v I bl =0 40 l i l (),NVNQN ()H QC l I Examples of reactive color developing components (79)C1O2s having an active halogen atom or atoms, which are employed in thepresent invention include, for example, V OR the following substances: s

v C0NH(CH2)NHC0 N N c1 c1 LNHfi-C Iz The reactive colordevelopingcomponents having an N amino or/and a hydroxyl group which areemployed in thepresent invention include, for example, the followingsubstances: c1

N v A 73) (I31 I H2(|3---l|'|J-NH2 o=c N A 11 I I Cl l NH 5 (81) 1121Cfi-NHz COONH1. (83) I @COCHzCONH-QNH:

o=o /N The present invention will be illustrated below with reference toexamples, but these examples do not restrict the invention.

Examplesof reactions of reactive coloring materials having an activehalogen atom or atoms with organic v photoconductive substances havingan amino or hydroxyl group or groups.

EXAMPLE 1 such a manner that the temperature did not rise above 5C.After the whole volume had been added, the resultant solution wasstirred for 30 minutes, and to it a solution of 1.0 mol sodium carbonatein 500ml water was added at the same temperature. After stirred for 3.54 hours, the mixture was pouredinto a large amount of water to obtain amagenta-colored photoconductive coloring material. Recrystallizationfrom dioxane gave magenta-colored crystals. Melting point: 245 248C.

- EXAMPLE 2 The substance (1.0 mol)'of the formula (4) was dismula (36)was dissolved in 3.0 liters of dried dioxane,

the same treatment as in Example 1 .was followed to obtain a solidyellow substance.

EXAMPLE 3 The substance (1.0 mol) of theformula (5) was dissolved in 3liters of dried dioxane to which 700ml of dried acetone was added. Themixed solution was.

thoroughly mixed by stirring and kept at 0 5C. The substance (0.5 mol)of the formula (41) was dissolved in 3.0 liters of dioxane. Using thesolutions, the same treatment as in Example 1 was followed to obtain asolid blue substance;

EXAMPLE 4 The substance (1.0 mol) of the formula (7) was dis- I solvedin a mixture of 3 liters of. dried dioxane and 4 mol of triethylamine.On the other hand, the substance (1 mol) of the formula (49) wasdissolved in 4.0 liters of o-dichlorobenzene. Using these solutions, thesame treatment as in Example 1 was followed to obtain solid reddishorange matter.

EXAMPLE 5 The substance (1.0 mol) of the formula (1 l was dissolved in 3liters of dried dioxane to which 700ml of dried acetone was added. Thesolution was thoroughly mixed by stirring and kept at 0 5C.'Next, thesubstance (0.5 mol) of the formula (43) was dissolved in 3.0 liters ofdried dioxane. Using these solutions, the

same treatment as in Example 1 was followed to obtain a solid yellowsubstance.

EXAMPLE 6 The substance (1.0 mol) of the formula (21) was dissolved in 3liters of monochlorobenzcne to which 300g cooled, the mixture wasfiltered and the filtrate wasevaporated to the half volume under reducedpressure. The remainder was added to methyl alcohol to obtain a redphotoconductive substance. Recrystallization from a mixture ofmonochlorobenzene and dioxane gave a red photoconductive substance (m.p:200C).

EXAMPLE 7 The substance (1.0 mol) of the formula (26) was dissolved in4.0 liters of dioxane to which 320g of triethylamine was added. Themixture was cooled to -5C under agitation. On the other hand, thesubstance 1.0 mol) of the formula (58') was dissolved in 4.5 liters ofdioxane. Using thesesolutions, the same treatment as in Example 6 wasfollowed to obtain a yellowish red organic photoconductive substance.

Examples of reactions of an organic photoc onductive substance having anactive halogen atom or atoms with a reactive coloring material having anamino or a hydroxyl group of groups.

EXAMPLE 8 The substance (1.0 mol) of the formula (59) was dissolved in amixture of 3.0 liters of monochlorobenzene and 4.0 liters of pyridine.While the solution being stirred at 0 5C, 1.0 mol of thesubstance'of-the for mula (27) was added. Then the stirring wascontinued at the elevated temperature 90 95C for 90 minutes to completethe reaction. The whole mixture was then poured into iced hydrochloricacid when a purple solid was separated. After separated by filtration,the solid matter was washed thoroughly with water and dried.Recrystallization from monochlorobenzene gave violet photoconductivepowders with the yield 62 65 percent.

EXAMPLE 9 The substance (1.0 mol) of the formula (34) was dissolved in 3liters of dried dioxane to which 700ml of dried acetone was added. Thesolution was thoroughly mixed by stirring and kept at 5C. 0n the otherhand, the substance (1.0 mol) of the formula (61) was dissolved in 3.0liters of dioxane. Using these solutions, the same treatment as inExample 1 was followed to obtain an orange photoconductivesubstance.

EXAMPLE EXAMPLE 1 l The substance (1.0 mol) of the formula (34) wasreacted with the substance (1.0 mol) of the formula (67) in the samemanner as in Example 10 to obtain an orange photoconductive substance.

Examples will be shown below in which the colored organicphotoconductive materials of the present invention are used asdeveloping materials for electrophotography.

EXAMPLE 12 The chemically bound colored substances described in Examples1 through 11 were pulverized into powders of 5p. diameter in averagewith an atomizer and l 10g, preferably 2 5g, of the powders were mixedthoroughly with 100g of magnetic iron powders (as carrier) of 100 150mesh in the average diameter of particles. The mixture was adsorbed on abar magnet to be used as amagnetic brush, with which several timescanning on electrostatic figures produced visible images. The images,when treated by the known process of fixation, were converted intopermanent ones.

EXAMPLE 13 The chemically bound colored substances (10g) described inExamples 1 through 11 were dispersed with a ball mill in 100ml ofinsulating liquid such as .herosene and mineral spirit, and 10ml of itwas again visible figures, when applied in an appropriate manner such asdipping, rolling or spraying.

EXAMPLE 14 A photosensitive paper for electrophotography prepared by useof zinc oxide and acrylicresin was charged with a corona discharger withthe applied voltage 7KV. Then the paper was exposed to a colored figurethrough a red filter. The electric charge remains on the paper only inthe shape of figure which should be colored in blue. The charged figurewas developed with the developer for blue color (the liquid photographicdeveloper obtained in Example 3 prepared by adding 1.5 2.0g. of a bluesubstance in ml of a petroleuin solvent and by dispersing with a ballmill for 15 20 hours) and was fixed. After being dried, the paper wasagain charged with electricity, exposed to a colored figure through agreen filter and developed with a developer for magenta color (preparedin the same manner as above using the toner obtained in Example by whichprocess the only part that was sensitive tothe magenta developerappeared in color by the developing. After the figure was fixed, thepaper was again electrostatically charged, exposed through a blue filterand developed in the same manner (with a similar developer using thetoner prepared in Example 2), by which process the only part that wassensitive to the photographic developer for yellow color appeared. Thecomposite figure: thus obtained almost perfectly reproduced the originalfigure.

The colored organic-photoconductive materials of this invention isemployed not only as a toner as above in both wet and dry processes, butalso as a suitable developing material to be used for thephotoelectrophoretic imaging process. This process employsphotoconductive pigment as toner in place of a socalled light sensitivelayer made of a photoconductor.

The following example illustrates the case in which the colored organicphotoconductive materials of this invention was employed as developerfor figure formation in the photoelectrophoretic imaging process.

EXAMPLE 15 To a petroleum solvent lsopar-H (commercial name) 12 15percent by weight of the substance obtained in Example 1 was added andthe mixture was treated with a ball mill for 4 5 days to make adispersoid of micro particles. This was applied on a light transparentelectrode in a. thin layer on which was placed an insulating paper andfurther on it another electrode. While a DC voltage 700V was beingapplied between the two electrodes, the paper was exposed to a lightimage through the transparent electrode. A colored image appeared on thesurface of the insulating paper and a negative mirror image on thesurface of transparent electrode.

The colored organic photoconductive materials of this invention can alsobe effectively employed as a component of the photosensitive layer forelectrophotography. V

Recently, colored copy papers are often used for duplicate purpose inoffices dependently on the use or content of the duplicates. Since thecolored organic photoconductive materials of this invention exhibitphotoconductivity for themselves, they can be em- EXAMPLE 16 To 10 partsof the colored organic photoconductive substance obtained in Example 1were added 80 parts of dioxane, 60 parts of dimethylformamide, and 30parts of methylcellosolve and further 28 parts of zinc oxide, and thewhole mixture was treated for 4.0 4.5

hours with a ball mill to make a dispersoid.

n base papers of 60 70g weight per square meter which had been treatedwith polyvinyl alcohol, the zinc oxide paint above was applied with aroll and dried by hot air. The photosensitivepapers thus prepared arecolored magenta. The colored photosensitive paper for electrophotographyprepared in this way was electrostatically charged with a coronadischarger to which -7KV was applied. Subsequently the paper was exposedto light together with the original figure and by the liquid developingprocess using pigment-petroleum solvent a positive image was produced.

The colored organic photoconductive materials of this invention areespecially suited, as the above examples show, to be used forphotographic developer and photosensitive materials. In these cases, thematerials of this invention can be naturally used not only alone butalso in combination with various known additives or other materials. Forexample, one or more members selected from the group consisting ofpigments, dyestuffs, resins, electrostatic charge controllers,dispersing agents and fixers may be dispersed or dissolved in thematerials of this invention.

In the next place, examples of the reactions of organic photoconductivesubstance containing amino or hydroxyl group or groups with reactivecolor developing components containing active halogen atom or atoms willbe shown.

EXAMPLE 17 To the substance (1.0 mol) of the formula (1) were added 3.0liters of dioxane, 0.3 liter of methylene chloride and further 0.6 molof a reactive coupler dissolved in 2.0 liters of dioxane. While themixture being stirred at 10 15C, 2 mols of sodium carbonate dissolved in300ml of water was added at the same temperature. After stirring wascontinued for 5 6 hours, the mixture was poured into a large amount ofwater, when white crystals were precipitated which were then separatedby filtration and washed with water. To the alcoholic alkali solution ofthe crystals, 50ml of a 2percent solution of potassium ferricyanide andthen 55ml of a 3 percent solution of dimethylparamine were added toobtain a magentacolored matter. Filtration, thorough washing with water,and drying gave a photoconductive coloring material.

EXAMPLE 18 Example 17 was separated by filtration, washed with water,and dissolved in an alcoholic alkali solution to which solution wasadded a diazonium salt of aniline to obtain a yellow organicphotoconductive coloring material.

EXAMPLE 19 The substance (1 mol) of the formula (4) was dissolved in amixture consisting of 2.4 liters of dried benzene, 700ml of driedmethylene chloride and dried pyridine. On the other hand, the substance(0.5 mol) of the formula (73) was dissolved in a mixture consisting of1.5 liters of dried dioxane and 1.5 liters of dried benzene. Using thesesolutions, the treatment was followed as in Example 17 to obtain thereaction product,

which was then treated in the same manner as in Example 18 to give a redorganic photoconductive coloring material.

' EXAMPLE 20 The substance (1.0 mol) of the formula (5) was dissolved ina mixture consisting of 3 liters of dried toluene and 4 mols oftriethylamine, and on the other hand the substance (0.5 mol) of theformula (78) was dissolved in a mixture consisting of 2.5 liters ofdioxane and 800ml of benzene. The latter solution was added to theformer while the temperature was maintained at 0 5C. Subsequently thetemperature was raised to C where the reaction was continued for 2hours. The mixture was added to an ice-cooled hydrochloric acid and theprecipitate formed was filtered,

thoroughly washed with water and purified by recrystallization fromdioxane. Further color developing reaction as in Example 17 produced amagentacolored photoconductive coloring material.

EXAMPLE 21 The substance (1 mol) of the formula (7) was dissolved in amixture consisting of 3 liters of dried dioxane and 4 mols oftriethylamine, and on the other hand the substance (1 mol) of theformula (77) was dissolved in 4.0 liters of o-dichlorobenzene. Using thetwo solutions above the treatment was followed as in Example 20 andfurther the same color developing reaction as in Example 17 wasconducted to obtain a blue photoconductive coloring material.

EXAMPLE 22 EXAMPLE 23 The substance (1 mol) of the formula (13) wasdissolved in a mixture consisting of 500ml of dried ether, 2.5 liters ofdried dioxane and 4 mols of dried triethylamine and, on the other hand,the substance (1 EXAMPLE 24 To a solution of the substance (1.0 mol) ofthe formula (21) in 3.0 liters of chlorobenzene and further 310g oftriethylamine maintained at C, the substance (l.0 mol) of the formula(77) dissolved in 2.5

liters of dioxane was added under stirring at the same temperature 0'5C. The same treatment as in ,.Example 20 produced white powders whichafforded a blue material when treated by the color developing reactionwith diethylparamine as in Example 17 and a red material when treatedwith a diazonium salt of aniline.

EXAMPLE 25 To a solution of the substance (1.0 mol) of the formula (26)in 4.0 liters of dioxane and 320g of triethylamine cooled at 0 5C, asolution of the substance mol) of the formula (76) in 2.5 liters ofdioxane was added and the mixture was treated as in Example to obtainwhite powders of the melting point 210 212C. The powders developedyellow coloration when treated with either color developing agent ofdiethylparamine or diazonium salt.

The following examples show reactions of organic photoconductivesubstances containing active halogen atom or atoms with reactive colordeveloping components containing amino or hydroxyl group or groups.

EXAMPLE 26 To a solution of the substance (1.0 mol) of the formula (80)in 3.0 liters of monochlorobenzene and 3.5 liters of dioxane, 350g oftriethylamine was added under agitation and the mixture was cooled to 05C.

, Subsequent addition of the substance (1.0 mol) of the EXAMPLE 27 To asolution of the substance (1.0 mol) of the formula (83) in 4.0 liters ofdioxane, 320g of triethylamine was added. This was treated with thesubstance (1.0 mol) of the formula (32) in the same manner as in Example26 gave white powders. The color developing reaction of the powders asin Example 17 afforded a photoconductive coloring material.

EXAMPLE 28 The substance (1.0 mol) of the formula (85) was dissolved in5.0 liters of dioxane and 320g of triethylamine and cooled to 0 5C. Thesubstance (1.0 mol) of the formula (32) was added to it under agitation,and the mixture was treated as in Example 26 to give white powders. Thecolor developing reaction with diethylparamine produced yellowcoloration.

EXAMPLE 29 To a solution of the substance (1.0 mol) of the formula (84)in 5.0 liters of dioxane, 320g of triethylamine was added and themixture was cooled at 0 5C. Addition to it of the substance (1.0 mol) ofthe formula (32) under agitation and the same treatment as in Example 26produced white powders. The color developing reaction withdiethylparamine and a diazonium salt of aniline exhibited magenta andyellow coloration, respectively.

Examples will be shown below in which the color developing organicphotoconductive materials of this invention were employed as developingmaterials for electrophotography.

EXAMPLE 30 The intermediate obtained prior to the color developingtreatment described in Example 17, that is the reaction product of thesubstances of the formulas (I) and (72), was thoroughly washed withwater and dried. The 5g portion of it was dispersed in 1,000ml of apetroleum solvent (trade mark: Isopar) by treating with a ball mill for5 hours, to prepare a developing solution. On the other hand, aphotosensitive paper for electrophotography, which was prepared fromzinc oxide and acrylic resin, was electrostatically charged with acorona discharger to which 7KV was applied, and this was exposed tolight. The developing treatment with the above developer producedcolorless figures at the charged parts. The paper was soaked in a colordeveloping solution as in Example 17, when magentacolored visiblefigures appeared. Alternatively, the colorless figures formed on thezinc oxide paper were transferred under pressure to a copying paperwhich had a slightly adhesive surface.- The same color developingreaction as before produced magentacolored visible figures.

EXAMPLE 31 The substance obtained prior to the color developing reactionin Example 21 was dispersed in Isopar in the same manner as in Example30. Following the procedure in Example 30 colorless figures were formedon a zinc oxide paper, which were treated-with a color developing agenteither directly or after transferred to a copying paper as in Example 30to form visible figures in which figures were colored blue.

EXAMPLE 32 The substance obtained prior to the color developing reactionin Example 23 was dispersed in Isopar in the same manner as in Example30. Following the procedure in Example 30, colorless figures were formedon a zinc oxide paper, which were treated with a color developing agenteither directly or after transferred to a copying paper as in Example 30to form visible figures in which figures were colored yellow.

EXAMPLE 33 A photosensitive paper for electrophotography prepared fromzinc oxide and acrylic resin was electrostatically charged with a coronadischarger to which -7K\ was applied. This paper was exposed to anoriginal colored manuscript through a red filter when the electricalcharge remains on the paper at those parts of the figures which shouldbe colored blue. These parts were developed with the colorless developerdescribed in Example 31 and the colorless figures were transferred, asin Example 30, by the electrostatic method to a copying paper having aslightly adhesive surface. Then the zinc oxide paper was exposed in thesame way through a green filter, treated with a colorless developerdescribed in Example 30 and the colorless figures were transferred tothe same copying paper as above. Finally the zinc oxide paper wasexposed through a blue filter, developed with the colorless developerdescribed in Example 32 when only those parts of the figures whichshould be colored yellow were developed. These figures were similarlytransferred to the above copying paper. Thus, the figures which shouldbe colored blue, red and yellow were superimposedly obtained on a singlepaper. By the color developing reaction with dimethylparamine asconducted in Example 17, the figures were colored blue, red and yellowcorresponding to the above treatments, giving the same colored figuresas in the original manuscript.

EXAMPLE 34 I The chemically combined colored substances appearing inExample 17 through 29 were separately pulverized with an atomizer intoparticles of the average diameter 5 of which 1 lg, preferably 2 5g, wasthoroughly mixed with 100g of magnetic iron powder (as carrier) of theaverage particle diameter 100- 150 mesh. The mixture was adsorbed on abar magnet to be used as a magnetic brush. The electrostatically chargedfigures were converted into colored visible figures, when scanned abovethem several times with the brush. The colored figures could be madepermanent figures by treating the known method of developing.

EXAMPLE 35 EXAMPLE 36 A photosensitive paper for electrophotographyprepared from zinc oxide and acrylic resin was electrostatically chargedwith a corona discharger to which 7KV was applied. This paper wasexposed to an original colored manuscript through a red filter, when thecharge on the paper remains only at those parts of the figures whichshould be colored blue. These parts prepared by dispersing a mixture ofml of a petroleum solvent and 1.5 2.0g of the toner with a ball mill for15 20 hours) and fixed. The paper, after being dried, was again charged,exposed-through a green filter and treated with the magenta developingsolution (prepared as above from the toner obtained in Example 17) whenonly those parts were developed which were sensitive to the magentadeveloper. After fixing, the paper was again charged, exposed through ablue filter and treated with the developer (prepared as above from thetoner obtained in Example 23) when only those parts were developed intofigures which were sensitive to the yellow developer. The copied figuresthus obtained almost reproduced the original manuscript.

The colored organic photoconductive materials of the present inventionare not only used as toner materials in both dry and wet processes, butalso suitable to the developing materials for figure formation inelectrophoresis. The present method employs a photoconductive pigment astoner instead of using a so-called photoconductive photosensitive layer.

The materials of this invention exhibit very excellent quality when usedfor the photoelectrophoretic imag- EXAMPLE 37 The substance obtained inExample 17 was added to a petroleum solvent, Isopar-l-l (commercialname), in the amount of 12- l5percent by weight and dispersed bytreating-with a ball mill for 4 5 days to make a microdispersoid. Thiswas applied on a light ti'ansparent electrode in a thin layer and aninsulating paper was placed on it and then another electrode further onthem. They were exposed to a light image while a DC voltage, 700V, wasbeing applied between the two electrodes. A colored image whichcorresponded to the light image was obtained on the insulating paper anda negative mirror image on the surface of the transparent electrode. v

The colordeveloping organic photoconductive materials of this inventioncan also be used effectively for a component of the photosensitive layerfor elec tropho tography.

Recently colored copying papers are often preferred in offices toclassify the copies more easily depending on use and purpose of thecopies. Since the color developing photoconductive materials of thisinvention are photoconductive by themselves, they can be employed tomake copying papers for electrophotography when applied on a supportingbase such as paper, either alone or in combination with otherphotoconductive EXAMPLE 38 To 10 parts of the color developing organicphotoconductive substance obtained in Example 17, 5 parts ofcopolymerized resin of styrene and butadiene, 80 parts of dioxane, 60parts of dimethylformamide, 30 parts of methylcellosolve and 28 parts ofzinc oxide were added. The mixture was treated with a ball mill for 4.04.5 hours. The zinc oxide paint thus prepared was then applied with aroller onto paper of 60 70g weight per square meter to which polyvinylalcohol had been applied to the surface, and the product was dried withhot air. The photosensitive paper thus obtained was colored in magentacolor. This colored photosensitive paper for electrophotography waselectrostatically charged with a corona discharger to which 7KV wasapplied, exposed to light together with aphotographic manuscript, andtreated with a liquid developer containing a pigment and a petroleumsolvent to produce a positive figure.

The colored organic photoconductive substances of this invention arealso characterized by producing different colors by being treated withdifferent color developing agents. This fact is illustrated by thefollowing examples.

EXAMPLE 39 The substance (1 mol) of the formula (1) was dissolved. in 3liters of dried benzene to which 700 ml of dried pyridine was thenadded.The mixture was thoroughly mixed by stirring and maintained at 5C. Onthe other hand, the reactive coupler (0.6 mol) of the formula (72) wasdissolved in liters of dried benzene and 1.5 liters of dried dioxane.This solution was added in small increments to the former solution insuch a way that the temperature did not rise above C. After the totalvolume had been added, the temperature was gradually raised up to 90 95Cunder agitation, after 2 hours allowed to cool and then poured intoice-cooled hydrochloric acid to make a slightly acid solution, whenimmediately the reaction product was precipitated. This was separated byfiltration, thoroughly washed with water and dried.

A mixture consisting of 5 g of the above product, 0.5g of linseed oildenatured alkyd resin, 0.5g of phenol denatured rosin and 10g of toluenewas dispersed with a ball mill for 8 hours. The condensed solution (5g)thus prepared of the color developing colorless developer was dispersedin 1,000ml of a petroleum solvent, Isopar, to obtain the colordeveloping colorless developer. This developer exhibited magenta colorwhen treated with dimethylparamine or diethylparamine, and yellow colorwhen treated with diazonium salt.

EXAMPLE 40 The reaction product obtained in Example 21 (the substancebefore submitted to the color developing reaction) was dispersed as inExample 39 together with alkyd or rosin and 5g of the concentrated colordeveloping agent for photographic developer thus prepared was dispersedin 1,000ml of Isoper to obtain a color developing colorless developer.This agent developed blue and red colors when treated with dimethyl anddiethylparamines, respectively.

EXAMPLE 41 A commercial zinc oxide copying paper was charged andexposed, as in Example 36, and developed with the colorless developerobtained in Example 39, and then with the developer for color developingin the same manner as in Example 17 to obtain magenta-colored figures.

EXAMPLE 42 A mixture consisting of 50g of the colorless photoconductivesubstance obtained in Example 17 (the substance before submitted to thecolor developing reaction), 8g of styrene resin and 10g of methylacrylate ester resin was dissolved in 40g of methyleth ylketone and 30gof dimethylformamide. The resulting mixture was applied to 15 18pthickness to a high quality paper the surface of which had beenprocessed with polyvinyl alcohol. The prepared photoconductive paper.was electrostatically charged with a corona discharger to which 7KV wasapplied, and then exposed to light. On the other hand, 10g of titaniumoxide and 20g of styrene resin was added to 50g of xylene and themixture was dispersed for 8 hours with a ball mill, from which theresulting concentrated developing agent (10g) was dispersed in 2,000mlof Isopar as carrier. The white developer thus prepared was used todevelop the above exposed photosensitive paper to obtain white figures.After complete melting of styrene resin and fixing, the color developingreaction was conducted as in Example 17 to develop magenta-coloredfigures in addition to white figures.

EXAMPLE 43 v The color developing photoconductive substance (50g)obtained in Example 17 was mixed with 8g of polyvinyl butylate and 10gof acrylic acid-vinyl acetate (inthe association ratio 1 1), and wasdissolved in a mixture of 140g of methylet hylketone and 130g ofdimethylformamide. This was applied to 15 18p. thickness to a highquality paper the surface of which had been treated with oilyvinylalcohol. The prepared photosensitive paper was electrostatically chargedwith a corona discharger, to which +7KV was applied, and exposed tolight. The color developing substance (10g) prepared from the substancesof the formula (7) and of the formula (77) was dissolved in 30g ofpolyvinyl butylate and the mixture was dispersed for 8 hours with a ballmill to obtain a concentrated developer. The 10g portion of thedeveloper was dispersed in 2,000ml of lsopar, with which the aboveexposed paper was developed to obtain white figures. By being heated to60 C and treated to develop colors in the same manner as in Example 17,the base of the photosensi tive paper was colored in magenta color andthe figures in cyan.

As is evident in the above examples, the color developing organicphotoconductive materials of this invention are especially suitable todeveloping or photosensitive materials. Naturally the materials of thisOH invention can be used not only alone, but in combina- I I tion withvarious known additives or other materials. For example, one or morepigments, dyestuffs, resins, l and and charge controllers, dispersers,fixers, sensitizers and desensitizers may be dispersed or dissolved inthe materials of this invention. N 01 What is claimed is: 1. A lighttransparent photoconductive material for f ff and use inelectrophotography which is the reaction product obtained by condensing\C a. an organic photoconductive compound selected 1 from the groupconsisting of photoconductive polycyclic aromatic compounds having anamino 1 5 t i substituent, and photoconductive pol c li b. a reactivecolored compound containing an active matic compounds having a hydroxylsubstituent, halogel] atom and bemg Selected from the group andconsisting of b. a colored substance selected from the group consistingof compounds 35-44 of the specification. Cl 2. A light-transparentphotoconductive material for use in electrophotography which is thereaction product obtained by condensing v T /0 Ha a. an organicphotoconductive polycyclic aromatic 4 01k )NHC-C=N-N compound containingan amino and/or hydroxyl N l; 4 group and being selected from the groupconsisting of:

N=N-C Cl-K J-NH N= Q N NH: Q Q l A HZN \N Cl-L J-NH i 1 IN /CH! 01% )NH-so,NII-0c=N@-N N l l N 0:0 on,

and

01 NH I I (\N (EH:

3. A material as claimed in claim 2, wherein compound (a) is thecompound of formula (1) of the specification while compound (b) is thecompound of formula (35 )ofthe specification.

l I I

2. A light-transparent photoconductive material for use inelectrophotography which is the reaction product obtained by condensinga. an organic photoconductive polycyclic aromatic compound containing anamino and/or hydroxyl group and being selected from the group consistingof:
 3. A material as claimed in claim 2, wherein compound (a) is thecompound of formula (1) of the specification while compound (b) is thecompound of formula (35) of the specification.